Convert Carats to Stones
Convert Carats (ct) to Stones (st) instantly and accurately.
Conversion Formula
st = ct × 3.149460888e-5
About Carats
A metric carat (ct or CD) is exactly 200 milligrams (0.2 g), the universal standard for weighing gemstones. Established internationally in 1907, it replaced fractionally different regional carat weights previously used in different countries. The total weight of a diamond or colored gemstone is always expressed in carats: a 1.00 ct diamond of excellent cut and color can command over $5,000. The Cullinan diamond, the largest gem-quality rough diamond ever found, weighed 3,106.75 carats.
About Stones
A stone (st) equals 14 pounds or approximately 6.350 kg. It is the standard unit for expressing human body weight in the United Kingdom and Ireland, where a person will say they weigh '11 stone 4' (meaning 11 stone and 4 pounds, or 158 lb / 71.7 kg). Despite the UK's official adoption of the metric system, stones remain the dominant unit for personal body weight on British bathroom scales, in doctors' offices, and in everyday conversation. British newspapers and sports reports routinely describe athletes' weights in stones and pounds.
Quick Reference Table
| Carats (ct) | Stones (st) |
|---|---|
| 1 ct | 3.149 × 10-5 st |
| 2 ct | 6.299 × 10-5 st |
| 5 ct | 0.000157473 st |
| 10 ct | 0.000314946 st |
| 25 ct | 0.000787365 st |
| 50 ct | 0.00157473 st |
| 100 ct | 0.00314946 st |